1你好我是maven的新手， 就像在开发人员指南中给出的那样，我从GitHub下载了Violet UML编辑器源代码，并尝试从我的Mac笔记本电脑的命令行中 mvn clean install ，但它引发了以下错误：
[ERROR] Failed to execute goal on project violetproduct-web: Could not resolve dependencies for project com.horstmann.violet:violetproduct-web:war:2.5.3: The following artifacts could not be resolved: com.horstmann.violet:violet-framework:jar:2.5.3, com.horstmann.violet:violetplugin-classdiagram:jar:2.5.3: Failure to find com.horstmann.violet:violet-framework:jar:2.5.3 in http://violet.sourceforge.net/maven2/repo/ was cached in the local repository, resolution will not be reattempted until the update interval of violet.repo has elapsed or updates are forced -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException
我试过 mvn clean site 也仍然显示相同的错误 请帮帮我。周五提交作业